The present invention relates to electrical transformers and, in particular, to the cooling of distribution transformer tanks.
A transformer tank typically comprises a cylindrical body and top and bottom plates for sealing therein a transformer and cooling liquid. Low and high voltage leads protruding from the body are adapted to connect the transformer to external low and high voltage lines. The heat generated during operation of the transformer is absorbed by the cooling liquid and conducted through the wall of the tank for dissipation to atmosphere. The rate at which the heat is dissipated, i.e., the cooling capacity, is an important aspect of transformer performance, because the greater the cooling capacity, the higher the efficiency and loadability of the transformer.
In order to improve the cooling capacity of a transformer tank, it has heretofore been proposed to provide the exterior surface of the tank with heat exchanger fins. For example, in U.S. Pat. No. 3,361,867, it has been proposed to form a tank body of multiple sections which are integrally formed with fins on the outside surface. The sections are interconnected to form the tank. The implementation of such a proposal, however, would increase the cost and complexity of manufacturing and assembling the tank, and would not be suited to the retro-fitting of existing tanks. Even if the fins were, instead, formed separately and welded to the outside surface of the tank, the weld joints would be susceptible to corrosion.
It would, therefore, be desirable to be able to enhance the cooling capacity of new and existing transformer tanks in a relatively simple and economical manner.